With the trackpad on macbook (without connecting to a mouse), the GUI for 3d_discrete would not allow user to zoom in or out of the structure. While it is possible to rotate the structure, it may not be the most intuitive as well (click and drag with two fingers).
In addition to using mouse/trackpad, it may be worth considering to allowing keyboard control (as alternative), e.g., arrow keys to rotate, some letter keys (or plus/minus) for zoom in/out.
With the trackpad on macbook (without connecting to a mouse), the GUI for 3d_discrete would not allow user to zoom in or out of the structure. While it is possible to rotate the structure, it may not be the most intuitive as well (click and drag with two fingers).
In addition to using mouse/trackpad, it may be worth considering to allowing keyboard control (as alternative), e.g., arrow keys to rotate, some letter keys (or plus/minus) for zoom in/out.